1. Field of the Invention
The present invention concerns a press tool comprising interchangeable working parts.
For the manufacture of metal or sheet metal pieces, tools that are normally mounted upon a press or stamping machine are utilized to carry out punching, swaging, cambering, bending and similar operations. These tools generally comprise working parts constituted by stamps and dies that are subject to more or less rapid wear, attachment parts such as, punch-holders and die-holders, stay blocks that are respectively mounted on the slide and press table, and a blank-holder normally intended for solidly maintaining in place a metal sheet subject to a shape-forming operation of the tool and for guiding these stamps during sliding.
According to known techniques, each press tool is designed so as to correspond to a given piece to be manufactured having preestablished dimensions and shape. When using such tools, any modification of the shape or type of piece to be manufactured normally requires a complete change of the tool on the assembly including all working parts. For this reason the working parts of known tools, i.e. the stamps, dies, and their attachment parts, are generally conceived or disposed fixed in order to obtain an essentially solid mechanical assembly rather than a rapidly mounted or dismantled assembly of these tools or their stamps and dies. This means that in said known tools, servicing, adjustment or replacement of a die or a stamp often requires a relatively long assembly or dismantling operation time.
2. Brief Summary of the Invention
The object of the present invention is to overcome these drawbacks by providing a press tool in which the working parts are interchangeable, easily mounted, dismantled and adjusted, solidly maintained in place and requiring a relatively short time for mounting and dismantling for their servicing, adjustment, replacement or substitution.
According to the present invention, a press tool having working parts constituted by stamps and dies and attachment parts such as blank-holders, punch-holders and die-holders, and stay blocks of the tool, comprise, as working parts, interchangeable stamps and dies produced respectively from metallic pieces or removable disc like elements. Attachment parts, comprising detachable blank-holders and stamp-holders, and cradles, (intended to receive and maintain in place blank-holders and stamp-holders) and other attachment parts for the cradle, each provided with at least one recess presenting a form complementary to that of the supporting cradles. These other attachment parts are intended to receive and secure in rotation and translation one of the cradles, and, for each blank-holder and stamp-holder, an adjustable clamp system cooperating with its cradle in order to secure it radially and axially.